In 1886, Starling proposed a hypothesis for the capillary-interstitial fluid transfer in which capillary filtration is attributed to arterial pressure, based on Poiseuille's work in long uniform tubes. In 1967-8, the precapillary sphincter, pores and negative interstitial pressure were reported. In 1984, clinical observations inconsistent with Starling's hypothesis prompted a physical study to verify pressure dynamics in a porous orifice (G) tubes. Results demonstrate that, unlike in Poiseuille's tube, a fluid passing inside the lumen of the G tube exerts a negative energy pressure gradient on its wall; most negative over its proximal part causing inflow of fluid by suction and positive over its distal part causing fluid outflow. A net negative pressure gradient also occurs in a surrounding chamber C, causing fluid to flow in an opposite direction to lumen flow. An autonomous dynamic magnetic field-like G-C circulation occurred between lumen and surrounding fluid compartments. Reviewed literature support the contention that this sole phenomenon adequately explains the capillary-interstitial fluid transfer under both physiological and pathological haemodynamic conditions. (C) 2001 Harcourt Publishers Ltd.
